Two yellow-crusted eruptions
A 40-year-old man with a long history of atopic dermatitis and generalized lichen simplex chronicus noted rapid development of yellow-crusted patches superimposed on his atopic dermatitis. Microscopic examination showed gram-positive bacteria in clusters. A Tzanck smear and viral culture (read out days later) was negative. The patient stated that similar albeit more localized eruptions in the past had resolved with oral cephalexin. Bacterial culture identified the pathogen as Staphylococcus aureus.
A 75-year-old woman of Irish descent with a basal cell carcinoma (BCC) on her face did not want to have the lesion excised or treated with radiation. After a discussion of other possible treatments, she opted to have the area frozen with liquid nitrogen and treated with topical imiquimod (Aldara). Once the area had been frozen, she applied topical imiquimod every other day. Two weeks later, she returned to the clinic with a crusted yellow plaque on her face. Gram’s stain was negative.